Plastic safety closure



States Patent 3,520,435 PLASTIC SAFETY CLOSURE James A. McIntosh, UpperMontclair, N.J., assignor to Mack-Wayne Plastics Company, Wayne, N.J., acorporation of New Jersey Filed Dec. 30, 1968, Ser. No. 787,695 Int. Cl.B65d 55/02 US. Cl. 2159 1 Claim ABSTRACT OF THE DISCLOSURE A plasticsafety closure for threaded neck containers is described having an innercap and an encompassing outer cap, each cap having engaging means, theengaging means being engaged for simultaneous rotation of the caps whenthe cap tops are in juxtaposition, and a plug associated with the outercap capable of extending through the top of the outer cap to contact thetop of the inner cap, thereby to maintain the cap tops separated and theengaging means in non-engaging relationship.

This invention relates to an improvement in plastic safety closures forcontainers having threaded necks. More particularly, this inventionprovides an improved safety closure which in fixed closed position has afreely rotatable outer cap but which closure upon manipulation causesthe outer cap to engage with an inner cap to remove the closure.

In the modern household, there are many products in daily use which canbe harmful or dangerous when taken internally. These products includehousehold detergents, pesticides, pharmaceutical preparations, solvents,and the like. Although hazardous substances are required to bear warninglabels, these products are a continual source of danger to smallchildren. Recently interest has been focussed on this problem bycommittees formed with representatives from government, industry and theprofessions to develop and promulgate standards for safety closures. Theplastic safety closure of this invention is directed to providing achild-proof cap for use with hazardous products ordinarily marketed inthreaded neck containers. The plastic safety cap of this invention issimple in construction and inexpensive to manufacture.

The plastic safety closure of this invention provides a closure for useon a threaded neck container having a threaded outer wall, an inner walland an interconnecting rim. The closure member itself is composed of twoseparate parts, i.e. an inner cap and an outer cap, the inner cap beingtelescoped within the encompassing outer cap.

The inner cap includes a top wall, a tapped cylindrical skirt depedingfrom the top wall for threaded engagement with the outer wall of thethreaded neck container, and at least one engaging means positionedsubstantially vertically near the outside lower edge of the cylindricalskirt.

The outer cap includes a top wall, the top wall having a substantiallycentrally positioned opening therein, a cylindrical skirt depending fromthe top wall of sufficient inside diameter to encompass the inner cap,at least one engaging means positioned substantially vertically near theinside upper edge of the cylindrical skirt, and an annular beadpositioned near the inside lower edge of the cylindrical skirt.

The outer cap is integrally molded with a crown and a relatively thinhinge connects the crown to the outer cap near the periphery of theouter cap. The crown has a substantially centrally posititoned plugdepending therefrom, adapted slidably to engage, close and extendthrough the substantially centrally positioned opening in ice the topwall of the outer cap, together with flexible means associated with theplug to maintain the crown and the outer cap in fixed closed position.

The plug is dimensioned longitudinally to contact the top wall of theinner cap when in fixed position to maintain the respective engagingmeans of the inner and outer caps in non-engaging relationship, and theannular bead on the inside lower edge of the outer cap cylindrical skirtis positioned to contact the bottom surface of the inner cap cylindricalskirt when the plug is in fixed position. Thus when the plug is in fixedposition, the outer cap rotates freely with respect to the inner cap andthe container is closed.

When the crown is raised, however, removing the plug, the outer capdescends toward the inner cap, the engaging means of the inner and outercaps engage, and the inner and outer caps rotate together so that thecontainer can be opened or closed.

A preferred embodiment of the plastic safety cap of my invention isshown in the accompanying drawings wherein:

FIG. 1 is a side view of the outer cap showing the relatively thinhinged crown, in closed position, the main body of the outer cap, and anindentation in the outer surface of the outer cap positioned under thefree end of the crown as a fingerhold.

FIG. 2 is a plan view of the outer cap of FIG. 1 showing the hingedcrown and the fingerhold.

FIG. 3 is a side view of the inner cap showing an embodiment of theengaging means on the outer surface of the inner cap.

FIG. 4 is a plan view of the inner cap.

FIG. 5 is a cross-sectional view showing both the inner and outer capwith the plug in fixed position in the outer cap opening preventingengagement of the inner and outer cap engaging means.

FIG. 6 is a cross-sectional view similar to FIG. 5 but showing both theinner and the outer cap with the plug removed from the outer cap openingand engagement of the inner and outer cap engaging means.

FIG. 7 is a cross-sectional view along line 77 of FIG. 1.

Referring now to the drawings, the plastic safety closure consists of anouter cap generally designated as 1 and an inner cap generallydesignated as 8.

FIGS. 1, 2 and 7 show outer cap 1 composed of top wall 2 and skirt 3depending therefrom. Outer cap 1 has integrally molded therewith crown4, attached to outer cap 1 by hinge 5, fingerhold indentation 6 and lugs7 on the inner surface of skirt 3.

FIGS. 3 and 4 show inner cap 9 composed of top wall 10 and skirt 11depending therefrom. Inner cap 9 has integrally molded therewith lugs 12forming grooves 13 on the outer surface of skirt 11. Also, inner cap 9has an annular bead 15 at the base of its outside surface, bead 15having a diameter such that its periphery is approximately coextensivewith the outer surface of lugs 11.

FIGS. 5 and 6 show inner cap 9 encompassed by outer cap 1 and details ofboth caps. For example, these figures show that the cylindrical skirt 11of inner cap 9 is tapped to provide threads 14 which mate with thethreads on the threaded neck container (not shown).

These figures further show that outer cap 1 has an opening 16 in topwall 2, and an annular bead 17 at the base of its inside surface. Also,crown 4 has plug 18 integrally molded therewith. Plug 18 has a neck 19of reduced cross'section such that its diameter approximates that ofopening 16.

The operation of the plastic safety cap of this invention is shown withreference to FIGS. 5 and 6. FIG. 5

shows the safety cap in closed position with plug 18 extending throughopening 16, plug 18 being held in place by bearing of the rim of opening16 on the under surface of the head of plug 18, plug 18 contacting topwall 10 of inner cap 9, and annular bead 15 of inner cap 9 contactingannular bead 17 of outer cap 1. In this closed position, it can be seenthat lugs 7 and 12 on outer cap 1 and inner cap 9 respectively arevertically separated such that outer cap 1 is freely rotatable withrespect to inner cap 9, and inner cap 9 remains threadedly engaged inclosed relationship with the threaded neck container.

FIG. 6 shows the safety cap in open position with plug 18 removed andouter cap 1 in lowered position with respect to inner cap 9 such thatlugs 7 mate with grooves 13 and rotation of outer cap 1 will causerotation of inner cap 9 and removal of the safety cap from the threadedneck container.

As will be apparent to one skilled in the art, the inner cap of thesafety closure of this invention can be constructed of any materialnormally employed in the manufacture of bottle caps, i.e. any of thecommon metals, or a semi-rigid plastic such as Bakelite or polystyrene.The outer cap, however, should be formed from any of the well knownresilient plastic materials such as polyethylene or polypropylene.Preferably the entire closure, including the inner and outer caps, ismolded as separate units employing a semi-flexible, semi-rigid plasticsuch as polypropylene.

Where the threaded neck container is used to store moisture sensitivedry products or where tight sealing is necessary during storage ofliquid products, advantageously the inner cap incorporates the featuresof the cap described and claimed in U.S. Letters Patent No. 3,286,866.Where such products are volatile, advantageously the inner capincorporates the features of the cap described and claimed in U.S.Letters Patent No. 3,398,818.

I claim:

1. A plastic safety closure for use on a threaded neck container havinga threaded outer wall, an inner wall and an interconnecting rim, saidclosure comprising an inner cap and an outer cap, the inner cap beingtelescoped within the encompassing outer cap;

(a) the inner cap including a top wall, a tapped cylindrical skirtdepending from the top wall for threaded engagement with the outer wallof the threaded neck container, at least one engaging means positionedsubstantially vertically near the outside lower edge of the cylindricalskirt;

(b) the outer cap including a top wall, the top wall having asubstantially centrally positioned opening therein, a cylindrical skirtdepending from the top wall of sufficient inside diameter to encompassthe inner cap, at least one engaging means positioned substantiallyvertically near the inside upper edge of the cylindrical skirt, and anannular bead positioned near the inside lower edge of the cylindricalskirt, the outer cap being integrally molded with a crown;

(c) the crown having a substantially centrally positioned plug dependingtherefrom adapted slidably to engage, close and extend through thesubstantially centrally positioned opening in the top wall of the outercap, and a relatively thin hinge connecting the crown to the outer capnear the periphery of the outer cap, flexible means associated with theplug to maintain the crown and the outer cap in fixed closed position;

((1) the plug being dimensioned longitudinally to contact the top wallof the inner cap when in fixed closed position to maintain therespective engaging means of the inner and outer caps in non-engagingrelationship, and the annular bead on the inside lower edge of the outercap cylindrical skirt being positioned to contact the bottom surface ofthe inner cap cylindrical skirt when the plug is in fixed position,thereby permitting free rotation of the outer cap with respect to theinner cap but such that when the crown is raised, removing the plug, theouter cap descends toward the inner cap, the engaging means of the innerand outer caps engage, and the inner and outer caps rotate together.

References Cited UNITED STATES PATENTS 8/1968 Jones et al. 215-9 1/1969Quackenbush 215-9

